1. Field of the Invention
This invention relates to a gripping device for use in an industrial robot or an industrial manipulator, more particularly to an improvement of the gripping device which has a pair of novel clamp arms and a novel misgrip detecting mechanism.
2. Description of the Prior Art
Conventional gripping devices for use in an industrial robot or an industrial manipulator have a pair of mere clamp arms swingably mounted on a base plate of the device and connected with a clamp arm opening and closing rod, which is extended and retracted by means of a cylinder-piston assembly, through a pair of links, respectively, so that the pair of clamp arms are made to open and close for gripping a workpiece. Therefore, they cannot positively grip a workpiece, nor can they be adapted to grip workpieces having any size and any configuration in the most preferable gripping positions of the clamp arms.
On the other hand, a misgrip detecting mechanism in the conventional gripping devices has been so constructed that the stroke of the clamp arm opening and closing rod connected with the pair of clamp arms through the pair of links is detected by means of limit switches, thereby detecting the misgrip. However, in such construction at least a limit switch is inevitable required, and moreover such construction is complex and thus disadvantageous.